“Remington expects the Connecticut appellate court to come to the same conclusion as the trial court. Plaintiffs’ claims fail under both Connecticut common law and the Protection of Lawful Commerce in Arms Act," Remington’s attorney issued in a statement to NBC Connecticut.

In October, a Superior Court judge dismissed the lawsuit against Remington Arms, citing an embattled federal law that shields gun manufacturers from most lawsuits over criminal use of their products.

Glimpse Into New Sandy Hook School

Adam Lanza killed 20 first-graders and six educators at Sandy Hook Elementary School with a Bushmaster AR-15-style rifle made by Remington. He killed his mother at their Newtown home earlier in the day and fatally shot himself at the school as police arrived.

The lawsuit accuses Remington of violating state law by selling and marketing a dangerous weapon to the public.

"Children and teachers were gunned down in classrooms and hallways with a weapon that was designed for our armed forces and engineered to deliver maximum carnage," the appeal says. "Fifty-pound bodies were riddled with five, 11, even 13 bullets. This is not sensationalism. It is the reality the defendants created when they chose to sell a weapon of war and aggressively market its assaultive capabilities."

Lawyers for Remington Outdoor Co., formerly known as Freedom Group, said the Madison, North Carolina-based company did not violate any laws. One of the lawyers, James Vogts, said Tuesday that he expected the appeal to be dismissed.

Some of the slain children's parents on Tuesday urged the state Supreme Court to hear their appeal.

“I am bringing this appeal for our dead son, Dylan, who never stood the chance as he stared down the barrel of a military-grade weapon,” Ian Hockley, father of Dylan Hockley, said during a news conference on Tuesday afternoon.

"Nothing will ever bring back my son, Dylan, or the other lives stolen from us on that awful day," Nicole Hockley said in statement. "Our only goal in bringing this appeal is to help prevent the next Sandy Hook from happening, and we have faith that Connecticut's Supreme Court will take up what is literally a matter of life and death."

David Wheeler, whose son, Benjamin, also died in the massacre, added in a statement: "As a father who lost a bright and shining child, all we ask is for our day in court to address the negligence of these companies."

At issue in the case is the Protection of Lawful Commerce in Arms Act, which was passed by Congress in 2005 and shields gun makers from liability when their firearms are used in crimes.

The families' lawyers had argued that the lawsuit was allowed under an exception in the federal law that allows litigation against companies that know, or should know, that their weapons are likely to be used in a way that risks injury to others

Advocates for gun control and against gun violence have criticized the law as special protection for gun makers. It became an issue in the presidential campaign earlier this year when Hillary Clinton criticized her main challenger in the Democratic primary, Bernie Sanders, for his past support of the law. Sanders, a Vermont U.S. senator, now wants to repeal it.

Besides Remington, other defendants in the lawsuit include firearms distributor Camfour and Riverview Gun Sales, the now-closed East Windsor store where Lanza's mother, Nancy, legally bought the Bushmaster XM15-E2S rifle.